package test1;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Leetcode1 {

}


class Solution {
    public List<List<Integer>> threeSum(int[] nums) {
        Arrays.sort(nums);
        int n=nums.length;
        List<List<Integer>> ret=new ArrayList<>();
        for(int i=0;i<n;){
            int left=i+1;
            int right=n-1;
            int target=-nums[i];
            if(target>0)break;
            while(left<right){
                int sum=nums[left]+nums[right];
                if(sum>target) right--;
                else if(sum<target) left++;
                else{//配对成功
                    //装进容器
                    ret.add(new ArrayList<Integer>(Arrays.asList(nums[i], nums[left], nums[right])));
                    left++;
                    right--;
                    //去重
                    while(left<right&&nums[left]==nums[left-1])left++;
                    while(left<right&&nums[right]==nums[right+1])right--;
                }
            }
            i++;
            while(i<n&&nums[i]==nums[i-1])i++;
        }
        return ret;
    }
}